We plan to study central auditory function in relation to neurological disorders using auditory evoked potentials. Auditory brainstem, middle-latency, long-latency and endogenous potentials will be recorded from the scalp of normal adults of all ages and compared with those recorded from patients with diseases of the nervous system. In particular, we plan to study the brainstem potentials in patients with histories of alcohol abuse, the brainstem through long-latency potentials in patients recovering from coma and the endogenous potentials in neurological diseases producing diminished mental function (dementia). In normal subjects, we will study the effects of binaural interaction on the auditory brainstem potentials and the effects of aging on the endogenous potentials. Animal studies will be conducted in parallel with the human studies in order to further define the neural generators of the brainstem, middle-latency and long-latency potentials, the effect of binaural interaction on the potentials, and the types of lesions appropriate for modeling human pathology. A conditioning paradigm using paralyzed cats will be used to investigate the neural source of endogenous potentials analogous to those found in humans.